Katy Perry Engagement Ring: Did John Mayer Propose?

Katy Perry fueled engagement rumors Sunday at the MTV European Music Awards (EMAs) after posing on the red carpet with a diamond ring on her wedding finger.

The "Roar" singer, 29, arrived wearing a mint green Zac Posen gown and made sure to greet her fans at the Ziggo Dome in Amsterdam. Her diamond accessory fueled speculation that her boyfriend John Mayer may have proposed, according to Daily Mail UK.

"It's inevitable," a source recently told E! News regarding the possibility of an engagement. "[They're] very serious."

The pair, who split in March before reconciling in July, has been has been inseparable in recent months which has led to speculation that they are more serious about their relationship this time around. Prior to their March split the singers would often duck and hide before paparazzi however this is no longer the case.

"Everyone wants them to get engaged," the source said. "They are so perfect together."

In August the couple debuted a love song duet "Who You Love" and at the time sources claimed Mayer was planning a proposal.

"She's changed his life forever. This is the most serious John has been about anyone and he wants to make it official," a source previously told the Daily Mail with another adding "Their romance is so strong - so it shouldn't be too long before he gets down on one knee."

Perry who was once married to British comedian Russell Brand, previously spoke candidly about her relationship with Mayer, 36, during a previous interview with Vogue magazine. The pop star professed her love for the "Paper Doll" singer despite their most recent split.

"I was madly in love with him. I still am madly in love with him. All I can say about that relationship is that he's got a beautiful mind," Perry told the July issue of Vogue regarding Mayer.

In July during his Born & Raised Tour in Milwaukee, Mayer gushed about Perry to the crowd. He has previously been linked to actress Jennifer Aniston and singer Jessica Simpson.

"[Katy's] more incredible than I ever thought," Mayer told the crowd according to RadarOnline.com.